What Is The Opposite Of Insomnia? Hypersomnia Symptoms, Causes, And Diagnosis

Insomnia is the most common sleep disorder. It affects more than 30 million people in the US¹ at any given time. The condition’s main symptom is inability to fall and stay asleep, which can significantly reduce your quality of life.

But what is the opposite of insomnia?

Some people struggle to cope with a lack of sleep, while others get sufficient rest but still feel sleepy during the day. This is typical of a condition called hypersomnia. Another key characteristic is excessive daytime sleepiness.

Let’s take a closer look at hypersomnia, including its symptoms, causes, and treatment options.

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What is hypersomnia?

Hypersomnia affects 4% to 6%² of the general population and 15% to 30% of people with sleep problems. The condition primarily causes severe daytime sleepiness or excessive nighttime sleep.

Most of us get a little sleepy from time to time and take a short daytime nap, perhaps because we didn’t get a good night’s sleep. But hypersomnia is more extreme than that.

Hypersomnia can make you feel like you need to sleep during the day regardless of what you’re doing or where you are. You might fall asleep several times a day, even after a good night’s rest.

The condition can affect your everyday activities, social life, and work. It can also make driving dangerous. Studies³ show hypersomnia patients have a higher risk of car accidents because they lack concentration and can fall asleep behind the wheel.

Hypersomnia is more common in men than in women. This is because men are more prone to sleep apnea syndrome, a common cause of daytime sleepiness.

The first symptoms of this condition usually occur in adolescence or young adulthood.

Is hypersomnia the opposite of insomnia?

Hypersomnia and insomnia are opposites in some ways since one causes too much sleep and the other causes too little sleep.

However, there’s a strong link between the two conditions. Both are sleeping disorders that often stem from underlying conditions and interfere with your quality of life.

The symptoms of each condition differ, but they both share a common symptom: poor-quality sleep⁴.

Primary vs secondary hypersomnia

Medical professionals classify hypersomnia as primary or secondary. Primary hypersomnia occurs without an obvious cause, while secondary hypersomnia usually stems from an underlying medical condition.

Primary hypersomnia

You may have primary hypersomnia if you don’t have any other medical conditions that could be causing your hypersomnia symptoms.

Forms of this type of hypersomnia include:

  • Idiopathic hypersomnia: This rare neurological sleep disorder causes excessive sleepiness. People with this condition can sleep for 11 hours or more each day and wake up feeling tired. A doctor can diagnose idiopathic hypersomnia if symptoms persist for over three months.

  • Kleine-Levin syndrome⁵ (KLS): People with these syndrome experience periods of excessive daytime sleepiness that can last for days or weeks. During these periods, people with KLS can sleep for as long as 20 hours a day. They may also have increased appetite and sex drive. This rare syndrome affects one to two people in a million.

  • Narcolepsy type 1: This chronic neurological disorder affects the brain’s ability to control the sleep-wake cycle. People with narcolepsy type 1 may experience excessive daytime sleepiness, cataplexy (a sudden loss of muscle tone triggered by strong emotions), sleep paralysis (the inability to move or talk when falling asleep or waking up), and hallucinations.

  • Narcolepsy type 2: This type of narcolepsy causes the same symptoms as narcolepsy type 1, except cataplexy.

Your doctor can recommend a treatment plan based on your primary hypersomnia type. This usually includes medication, cognitive behavioral therapy, proper sleep hygiene, and healthy lifestyle habits.

Secondary hypersomnia

Excessive daytime sleepiness could be caused by a variety of factors, including:

  • Medical condition: Conditions⁶ such as Parkinson’s disease, obesity, sleep apnea, multiple systems atrophy, epilepsy, head trauma, central nervous system injury, brain tumors, and strokes that cause lesions of the thalamus (part of your brain responsible for the wake-sleep cycle) can cause secondary hypersomnia.

  • Medication: Some prescription and non-prescription meds can cause excessive sleepiness. Examples include benzodiazepines, melatonin, medications for blood pressure, epilepsy, and Parkinson’s disease.

  • Illegal drugs and alcohol: People who misuse illegal substances and alcohol can suffer from excessive sleepiness. Illegal drugs, such as opiates and cannabis, can cause hypersomnia.

  • Insufficient sleep syndrome: Adults need between seven and nine hours of sleep per night. Insufficient sleep syndrome occurs when you don’t get enough sleep voluntarily. You can easily treat it by getting enough sleep. In the US, around 30% of adults⁷ get insufficient rest because they sleep six hours per day or less.

  • Mood disorders: Some mood disorders⁸ can cause excessive daytime sleepiness. These include major depressive disorder and bipolar disorder.

Managing secondary hypersomnia involves addressing the underlying disorder. Symptoms usually start to subside once you get the primary condition under control.

Symptoms of hypersomnia

Besides common episodes of extreme sleepiness during the day, hypersomnia symptoms can include:

  • Falling asleep at inappropriate times (at work, at school, during lunch, behind the wheel)

  • Long periods of nighttime sleep (over ten hours) that don’t ease your daytime sleepiness or help you feel rested and fresh

  • Difficulty waking up in the morning or after a daytime nap

  • Feeling disoriented, confused, and highly irritated after waking up

  • Feeling unrested after daytime naps, regardless of their length

  • Anxiety

  • Irritability

  • Fatigue

  • Restlessness

  • Inability to concentrate or focus

  • Headaches

  • Loss of appetite

  • Hallucinations

If you don’t address your insomnia symptoms, you may become unable to carry out everyday activities at home and work.

Causes of hypersomnia

The causes of primary hypersomnia are currently unknown. In some cases, the cause could be genetic.

Studies show around 33%⁹ of people who live with idiopathic hypersomnia have a family member with the same condition. Genetic testing cannot currently predict the possibility of a person developing primary hypersomnia.

How hypersomnia is diagnosed

Contact your doctor if you are experiencing sleep problems. They can either diagnose your condition or refer you to a sleep specialist.

The first step to diagnosing hypersomnia¹⁰ is determining whether it’s primary or secondary. To do this, your doctor will review your medical history, conduct a physical exam, and run lab tests. The workup would usually include:

  • Complete blood count

  • Screening biochemistry tests

  • Thyroid-stimulating hormone test

  • Drug screen

If an underlying condition is not causing your hypersomnia, your doctor will discuss the following tests with you:

Keeping a sleep diary

You must experience hypersomnia symptoms at least three times a week for three months¹¹ to be diagnosed. A sleep diary isn’t really a “test,” but it can help you and your doctor keep track of your sleep problems.

Your doctor may suggest wearing an actimetry sensor¹². This smart device tracks your sleep-wake cycle and identifies disruptions. These devices are shaped like a wristwatch and don’t interfere with your everyday activities.


Polysomnography is a sleep study. Doctors use it to diagnose a variety of sleep disorders, including hypersomnia. This test is performed in a hospital, a sleep clinic, or another dedicated facility.

While sleeping, medical equipment will collect important data, including your blood oxygen levels, brain waves, breathing rate, eye movements, sleep stages, and more. 

The procedure doesn’t cause any pain or discomfort. Most people find falling asleep in an unusual environment the hardest part of the test. However, people with hypersomnia usually don’t have as much trouble falling asleep.

Multiple sleep latency test

This test checks if you have excessive daytime sleepiness by determining how fast you fall asleep in a quiet setting during the day. You will need to dedicate a full day to this test.

A multiple sleep latency test consists of several nap trials. During each of them, you will lie in bed with the lights off and try to fall asleep.  Special sensors measure your sleep stages while you are sleeping.

The doctor will wake you after 15 minutes.

If you don’t fall asleep after 20 minutes, the trial ends. 

The multiple sleep latency test usually follows polysomnography so the doctor can evaluate your full sleep-wake cycle.

Epworth Sleepiness Scale

The Epworth Sleepiness Scale is a questionnaire that will help your doctor understand the extent of your sleepiness. It consists of eight situations in which you rate your tendency to feel sleepy on a scale from zero to three.

You can take the test at home and show your doctor the results. The results show whether your sleepiness requires further medical attention.

How to treat hypersomnia

Once your doctor has diagnosed primary hypersomnia, they will recommend a suitable course of treatment depending on your symptoms.

Note that treating secondary hypersomnia involves addressing the underlying conditions.

Treatment for primary hypersomnia may include:


In August 2021, the US Food and Drug Administration¹³ (the FDA) approved Xywav for treating idiopathic hypersomnia.

Xywav is a prescription medication. It was initially approved for treating excessive daytime sleepiness and cataplexy in people with narcolepsy. It is now prescribed to treat idiopathic hypersomnia too.

Oxybate is the active molecule in this medication. It works as a central nervous system depressant. The medication can promote deep sleep to help you feel more rested.

Xywav is a controlled substance that may cause dependence. Always follow your doctor’s instructions carefully.


Stimulants can treat daytime drowsiness and help improve your quality of life. However, many can cause dependency.

Your doctor may prescribe the following stimulants:

  • Dextroamphetamine (Dexedrine)

  • Methylphenidate (Concerta)

These medications may cause unpleasant side effects, such as loss of appetite, high blood pressure, irritability, and increased heart rate. Overdosing may lead to convulsions and seizures.

Wake-promoting medication

Non-stimulant wake-promoting medications are thought to influence the chemistry of the brain in a way that boosts wakefulness.

FDA-approved non-stimulant wake-promoting medications¹⁴ include:

  • Modafinil (Provigil)

  • Armodafinil (Nuvigil)

  • Solriamfetol (Sunosi)

  • Pitolisant (Wakix)

These drugs can interfere with other medications, such as birth control. They can also lead to several side effects, including headaches.

Cognitive behavioral therapy for hypersomnia (CBT-H)

Cognitive behavioral therapy is a highly effective treatment for sleep disorders. In fact, for insomnia, cognitive behavioral therapy for insomnia CBT-I is the first line of treatment.

A 2020 study¹⁵ was the first to test CBT-H for adults with various hypersomnias. It involved 35 people with narcolepsy and idiopathic insomnia. All of them participated in a six-session program arranged by a psychologist through videoconferencing.

The program taught participants how to practice sleep hygiene, provided management techniques for depression and anxiety, and helped improve their ability to achieve goals. Results showed CBT-H could help manage people with hypersomnia’s psychological symptoms.

The program has to be administered by a qualified medical professional to be successful. Ask your doctor for a referral or recommendation for someone in your area.

The lowdown

Hypersomnia is a sleep disorder characterized by excessive sleepiness during the day. The causes of this condition vary from underlying diseases to genetics.

Hypersomnia is the opposite of insomnia in some ways, but these two conditions have numerous similarities.

If you are experiencing hypersomnia symptoms, don’t wait for the condition to go away on its own. Besides reducing your quality of life, the condition could lead to new health problems and dangerous accidents.

Speak to your doctor to discuss your symptoms and get a diagnosis. They will be able to recommend a treatment plan to help you tackle your symptoms and resume a normal life.

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We make it easy for you to participate in a clinical trial for Insomnia, and get access to the latest treatments not yet widely available - and be a part of finding a cure.

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